In general, a communications controller comprises a central control unit associated with a storage storing the network control program and with an input/output interface connected to an input/output bus. The terminals controlled by the communications controller are connected to line adapters which in turn are connected to the input/output bus. Furthermore, one or several central processing units are connected to the input/output bus, the communications controller having the task of ensuring and managing the data exchanges between the terminals and the central processing unit(s).